The migration is optional, should you for whatever reason want to stay with GFWL, and save game content can be carried over providing the correct procedure is followed.

Owners of the current game must load it up and log into GFWL. Once that's done, close GFWL and the game. Right click on Dark Souls in Steam and opt in to the game's new beta (found under the ‘Betas' tab). Launch it again and it will update and you're good to go.

Note that Steam may ask you which version of the game's Steam Cloud backup to launch when booting. Don't mistake this with migrating your game data – the procedure above must still be followed.

And don't panic if you get it wrong and update the game to find that your old save data has gone. Simply opt out of the beta and the game will un-patch itself, restoring your saves. You can then try again until you get it right.

Those who use DSfix to unlock the game's resolution and framerate will have to download and install a new version of the mad, which fortunately is already up and running.

The GFWL version of the game will remain available until February 15th, after which the Steamworks release will become Steam's default version.